A Toxic Algae Bloom May Be Causing Sea Lions to Attack People

Learn more about an algae bloom that’s causing sea lions to act erratically, leading to a few cases of aggression.

By Monica Cull
Apr 9, 2025 9:30 PMApr 9, 2025 9:54 PM
Three swimming sea lions
An image of three sea lions swimming in the ocean unrelated to the toxic algae bloom. (Image Credit: David Keep/Shutterstock)

Newsletter

Sign up for our email newsletter for the latest science news
 

Sea lions are typically not aggressive toward humans. However, these usually curious and playful marine animals have been making headlines recently for multiple attacks on people off the coast of California. 

The aggression is linked to a toxic algae bloom impacting nearly 400 miles of the Southern California coast, mostly in L.A. and Santa Barbara Counties. Aggressive and erratic behavior isn’t the only way this toxic bloom can affect these animals, and sea lions aren’t the only infected animals. 

Sea Lion Attacks

Recently in March 2025, two people in Southern California were attacked by an aggressive sea lion. One man was on his surfboard when the sea lion charged, bit him, and dragged him off the surfboard. 

0 free articles left
Want More? Get unlimited access for as low as $1.99/month

Already a subscriber?

Register or Log In

0 free articlesSubscribe
Discover Magazine Logo
Want more?

Keep reading for as low as $1.99!

Subscribe

Already a subscriber?

Register or Log In

Stay Curious

Sign up for our weekly newsletter and unlock one more article for free.

 

View our Privacy Policy


Want more?
Keep reading for as low as $1.99!


Log In or Register

Already a subscriber?
Find my Subscription

More From Discover
Stay Curious
Join
Our List

Sign up for our weekly science updates.

 
Subscribe
To The Magazine

Save up to 40% off the cover price when you subscribe to Discover magazine.

Copyright © 2025 LabX Media Group